Determinación del tiempo máximo para recuperar y criopreservar espermatozoides obtenidos de la cola del epidídimo en caninos post orquiectomía

The aim of the study was to determine the maximum time to recover and cryopreserve spermatozoa from the tail of canine epididymis post orchiectomy. The testes were obtained through orchiectomy from 20 dogs aged 1 to 8 years. The testis were placed in sodium chloride 0.9% and stored at 5 °C for 0, 24, 48 and 72 hours. Spermatozoa were recovered by cutting the tail of the epididymis in an extender based on Tris-citrate-fructose. For the cryopreservation process, egg yolk (20%) and glycerol (5%) was added to the diluted sample (sperm + dilutor). The new dilution was packaged in 0.5 ml straws, which were subjected to a cooling curve and then placed in liquid nitrogen. Total motility, progressive motility and functional integrity of the membrane were evaluated. Before cryopreservation process, total motility after 24 and 72 hours of storage at 5 °C decreased (p<0.05). However, total motility found after cryopreservation process varied significantly only after 72 hours of storage at 5 °C (p<0.05). Similar trend was observed for progressive motility. The functional integrity of membrane, both before and after the cryopreservation process, did not suffer significant changes between groups. The results showed that it is possible to collect and cryopreserve epididymal sperm until 48 hours of orchiectomy.